1. Field of the Invention
This invention relates generally to rolling mills where the roll necks are rotatably supported in bearings contained in so-called "chocks", and is concerned in particular with an improvement in the manner in which such chocks are supported.
2. Description of the Prior Art
The invention is particularly useful in, although not limited to, "flat" mills, so-called because the products they roll are flat and relatively wide, e.g., plates, strips, and the like. It will be seen from FIG. 1 that the bearings 10 for the rolls 12 in flat mills are long to allow them to carry the large loads typically encountered when rolling flat products. The rolls also are necessarily long to accommodate the width of the products being rolled, and consequently they tend to bend and take on an angle .alpha. in the bearing area. To evenly distribute the load over the full lengths of the bearings, the chocks 11 which contain the bearings must be able to tilt to accommodate the angle of the roll neck under load.
In the past, as shown in FIG. 2A, cylindrical rocker plates 14 worked well in allowing the chocks 11 to tilt angularly because of the line contact as at 16. The line contact provided a pivotal location, but did not supply adequate support, so the size of the chocks had to be increased substantially to maintain the required stiffness. Alternatively, as shown in FIG. 2B, spherical seats 18 provided a larger support area which in turn allowed chock sizes to decrease. However, spherical surfaces must slide to allow the chock to tilt. Due to the high rolling loads, the resulting frictional resistance at the larger contact interface acted to prevent the chocks from tilting properly.